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The perception of technological risks: A literature review
TECHNOLOGICAL
FORECASTING
AND SOCIAL CHANGE
23, 285-297
(1983)
The Perception of Technological Risks: A Literature Review VINCENT T. COVELLO
ABSTRACT
In response to rising concern about technological risks, a concerted effort is being made to improve risk analysis methods and risk management approaches. As part of this effort, behavioral and social scientists have produced a substantial body of knowledge of value to risk analysts and decision makers. This paper focuses on behavioral and social science studies of human intellectual limitations in thinking about risks, factors influencing risk attitudes and perceptions, and factors contributing to social conflicts and disputes about technological activities. A basic assumption of the paper is that analysts and decision makers can benefit from a better understanding of how experts and nonexperts think and make decisions about technological risks. Without such understanding, well-intended policies may be ineffective or even counterproductive.
Introduction A truly unexpected result came out of the Kemeny Commission’s study of Three Mile Island. A group that set out to investigate a technology ended up talking about people. . . . In the commission’s own words, “It became clear that the fundamental problems were people-related problems.” Editorial,
Washington Post, October 31, 1979.
Behavorial and social scientists in several countries are currently grappling with several people-related questions related to risk: What factors influence individual perceptions of risk? What accounts for anomalies in the way individuals and groups behave when faced with ostensibly comparable risks-such as the risks of nuclear power, dam failures, or earthquakes? What weight should decision makers attach to public perceptions of risk in determining how safe is safe enough? Are there ways to increase our capacity for dealing with technological risks in a rational manner? What follows is a review of the behavioral and social science literature pertaining to these questions (See [l] through [166]). Before beginning, however, several points need to be made concerning the quality of the data and the research. First, most of the reported findings are based on surveys of small, highly specialized, and unrepresentative groups. An important set of risk perception studies undertaken by Paul Slavic and his colleagues,
VINCENT COVELLO is Program Manager for Risk Analysis Research at the National Science Foundation, Washington, D.C. Address reprint request to Dr. Vincent T. Covello, National Science Foundation, 1800 G St., NW, Washington, D.C. 20550. 0 1983 by Elsevier Science Publishing
Co, Inc.
0040-1625/83/$03.00
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for example, relied almost entirely on data gathered from residents of Eugene, Oregon, a small university town located in a state with a high level of environmental concern and a progressive environmental protection program [29, 127, 1291. The respondents included 40 members of the Eugene League of Women Voters, 40 college students at the University of Oregon, 25 Eugene business people, and 1.5 persons selected nationwide for their expertise in risk analysis. Second, little attempt has been made by researchers to analyze the effects of organizational and social structural variables (e.g., ethnicity, religion, sex, region of the country, age group, occupation, education, income, marital status, organizational membership, and organizational location) on risk perceptions. Most studies adopt a personal or technical perspective [71] and start from the assumption that individual risk perceptions can be explained by the psychological makeup of the individual or by the degree to which the individual has access to, and correctly interprets, technical information. With relatively few exceptions, researchers have not adopted an organizational or social structural perspective, which assumes that risk perceptions are substantially influenced by group norms and expectations, and by the social and organizational location of the individual. As Linstone [71] has shown, studies that ignore or unduly emphasize one of these three perspectives-personal, technical, or organizational-are considerably less useful than studies that attempt an integrated analysis. Unfortunately, risk perception research is still at an early stage of development, and this integration has not yet occurred. Third, the risk perception literature suffers, in an exaggerated form, from shortcomings common to nearly all survey research [28]: (1) people typically respond to survey questions with the first thing that comes to mind, and then become committed to their answer; (2) people typically provide an answer to any question that is posed, even when they have no opinion, when they do not understand the question, or when they hold inconsistent beliefs; (3) survey responses can be influenced by the order in which the questions are posed, by whether the emphasis in on speed or accuracy, by whether the question is closed or open, by whether respondents are asked for a verbal or numerical answer, by interviewer prompting, and by how the question is posed. Risk perception surveys are especially vulnerable to these types of biases, because people are often unfamiliar with the activity or substance being assessed and because they may not understand the technical and methodological issues under debate. Fourth, although risk perceptions may be inconsistent with behavior, relatively few studies have examined the relationship between perceptions of technological hazards and the behavior of people in actual situations. Empirical studies from other social and behavioral fields suggest that the linkages between perception and behavior are highly complex and appear to be mediated by several factors [6, 13, 621. Researchers have shown, for example, that activist behavior is related to a willingness to participate in group activities, a positive identification with potential group leaders, a belief in the efficacy of social action, and physical proximity to arenas of social conflict [13, 301. With few exceptions [78, 901, risk perception researchers have not examined these variables. Fifth, for reasons that are not entirely clear, researchers have made few attempts to relate the literature on the perceived risks of technological hazards to the extensive literature on the perceived risks of natural disasters [2, 3, 4, 9, 10, 12, 17, 34, 51, 52, 39, 64, 71, 81, 82, 83, 861. To date, only limited efforts have been made to replicate and extend natural hazard studies concerned with the various factors that affect perceived risks, including the perceived cause of the disaster, the degree to which risk information is available and accessible, the form in which risk information is presented, the institutional
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and social location of the individual evaluating the risk, the individual’s previous disaster experiences, and the perceived level of hazard protection and security. Furthermore, only limited efforts have been made to replicate or extend natural hazard studies concerned with the various factors that mediate between perceived risk and actual behavior, including the perceived benefits of risk mitigation actions, the presence or absence of evidence validating or confirming the threat, and the individual’s mental image of potential damages. Finally, the findings reported in this paper are confounded by several unresolved problems: risk perceptions may change rapidly; people may not understand how their perceptions and preferences translate into policy; and people may prefer alternatives not realistically obtainable. With these reservations and qualifications in mind, some of the major findings of risk perception literature are discussed below. Human Intellectual Limitations Research suggests that people do not cope well when confronted with risk problems and decisions. Intellectual limitations and the need to reduce anxiety often lead to the denial that risk and uncertainty exist and to unrealistic oversimplifications of essentially complex problems [120, 127, 1501. To simplify risk problems, people use a number of inferential or judgmental rules, known technically as heuristics [54, 55, 147, 148, 149, 1501. Two of the most important are 1) information availability, or the tendency for people to judge an event more frequent if instances of it are easy to imagine or recall; and 2) representativeness, or the tendency of people to assume that roughly similar activities and events (such as nuclear power technologies and nuclear war) have the same characteristics and risks. These judgmental operations enable people to reduce difficult probabilistic and assessment tasks to simpler tasks; however, these judgmental operations also lead to severe and systematic biases and errors. One bias associated with information availability is that people have difficulty imagining low probability/high consequence events happening to themselves [9, 120, 1271. Unless people have been made graphically aware of the risks, typically through past experience, they are unlikely to take protective action [63, 64, 1651. A classic example is the observed reluctance of floodplain residents to purchase low-cost flood insurance [64]. Compounding the problem is the difficulty people have understanding and interpreting probabilistic information. People residing in loo-year floodplains, for example, typically believe that a recent severe flood precludes the possibility of another severe flood in the near future [9, 1651. According to folk wisdom but not to probability theory, lightning never strikes the same place twice. Biases associated with information availability have also been used to explain the results of studies in which people were asked to judge the frequency of various causes of death, such as accidents, tornadoes, and diseases [127]. These studies show that the risks of low-frequency events tend to be overestimated, and that the risks of high-frequency events are underestimated. People underestimate fatalities caused by asthma, stroke, and diabetes, and overestimate fatalities from homicides, botulism, fires, snake bites, tornadoes, and abortion. Overestimated causes of death tend to be dramatic, sensational, and of interest to the media, whereas underestimated causes of death tend to be unspectacular, undramatic, and of little interest to the media [14, 1271. Researchers have also pointed out that information availability biases may cause risk information campaigns and educational efforts to work at cross-purposes [ 1331. Information may heighten the imaginability and consequently the perceived probability of a rare
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event, even when the information is designed to assure individuals that the event is unlikely. A package insert listing all the risks of taking a drug, or a published report describing safety precautions taken at a DNA research laboratory, may serve only to increase concern about the substance or activity. By identifying previously unknown ways in which things can go wrong, the information provider takes the chance that people will incorrectly assess the information (i.e., that they will consider the event more likely as a result of increased knowlege). As one observer notes [77, p. 611: We generally assume that informed advice is valuable to political policy-makers. However, in the context of a controversial political issue, and when the relevant technical analysis is ambiguous, then the value of scientific advice become questionable. A technical controversy sometimes creates confusion rather than clarity, and it is possible that the dispute itself may become so divisive and widespread that scientific advice becomes more of a cost than a benefit to the policy-maker and society.
Unfortunately, few researchers have critically examined the controversial hypothesis implicit in this work-that the very discussion of a low-probability hazard increases the judged probability of the hazard, regardless of what the evidence indicates. Disputes and controversies about risk are made all the more difficult by another psychological mechanism: once beliefs are formed, individuals frequently structure and distort the interpretation of new evidence and often resist disconfirming information [116, 1271. People tend to dismiss evidence contradicting their beliefs as unreliable, erroneous, and unrepresentative. The accident at Three Mile Island, for example, provided confirming evidence for those already convinced that nuclear power technology is safe [90]; the accident also reinforced the beliefs of those who believed that nuclear power technology is dangerous. Convincing people that a hazard they fear is not a hazard is extremely difficult even under the best conditions. Any accident or mishap, no matter how small, is seen as proof of high risk [133]. Overconfidence Another second set of risk perception findings addresses the problem of overconfidence. Researchers have shown that experts and laypersons are typically overconfident about their risk estimates. In one study participants were asked to state the odds that they were correct in judging which of two lethal events was the more frequent [127]. Most people claimed that the odds of their -being wrong were 1OO:l or greater. In actuality, people were wrong about one out of every eight times. Such overconfidence can produce serious judgmental errors, including judgments about how much is known about the hazard and about how much needs to be known. Of equal or greater importance, overconfidence leads people to believe that they are comparatively immune to common hazards. Studies show that 1) most people rate themselves among the most skillful and safe drivers in the population; 2) people rate their own personal risk from several common household hazards as lower than the risk for others in society; 3) people judge themselves average or above average in their ability to avoid bicycle and power lawnmower accidents; and 4) people underestimate and are extremely unrealistic about their chances of having a heart attack (115, 139, 1581. In general, people underestimate the risks of activities that they perceive to be familiar and under their personal control, such as automobile driving. Overconfidence has also been used to explain in part the observed reluctance of about 80 to 90% of the U.S. driving population to wear seat belts [124]. Unfortunately, few empirical studies have examined this issue or the more general relationship between perceived risk and protective behavior. One new study by Slavic, Lichtenstein, and
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Fischhoff of seat belt usage is, however, exploring and empirically testing the hypothesis that seat belt usage will increase if the public is presented with information about the lifetime risks of driving instead of information about the risks of taking a single trip. Expert and Nonexpert Estimates of Risk A third set of findings bears on expert and nonexpert estimates of risk. A consistent result is that technical experts and nonexperts differ substantially in their risk estimates [57]. Risk estimates of technical experts are closely correlated with annual fatality rates, whereas the risk estimates of nonexperts are only moderately to poorly correlated with annual fatality rates [ 1291. In explaining these differences, researchers have identified several factors other than annual fatality rates that influence public perceptions of risk [72, 127, 153, 1541. Risks are perceived to be higher if the activity is perceived to be involuntary, catastrophic, not personally controllable, inequitable in the distribution of its risk and benefits, unfamiliar, and highly complex. Other factors influencing risk perceptions are whether the adverse effects are immediate or delayed, whether exposure to the hazard is continuous or occasional, whether the technology is perceived to be necessary or luxury, whether the adverse effects are well-known or uncertain, and whether the activity is certain to be fatal. Several studies have shown that these dimensions of risk are closely related to each other [ 126, 153, 1541. Such correlations have prompted several research groups to reduce the various dimensions of risk to a smaller number of factors. One study identified at least two factors [29]: the level of technological complexity and the hazard’s severity or catastrophic potential. In a follow-up study that examined a larger set of hazards and risk characteristics, Slavic, Fischhoff, and Lichtenstein [ 1271 found three factors: familiarity, dread, and the number of people exposed to the hazard. In an ongoing European study of risk perception, Vlek and Stallen identified several additional factors influencing risk perception and risk acceptability, including the beneficiality of the technology and the degree to which protection is provided by institutional means [ 153, 1541. In spite of these different findings, it is clear that a hazard’s catastrophic potential is uppermost in the minds of people. Because catastrophic events may threaten the survival of individuals, families, societies, and the species as a whole, such concern may be quite justifiable. Analysis of intercorrelations between the various dimensions of risk have also led researchers to challenge Starr’s [135] well-known proposition that the risks of voluntary activities are more acceptable to the general public than the risks of involuntary activities [5, 99, 1271. One problem with this proposition is that voluntary risks are also perceived by the public to be controllable, equitable, familiar, and noncatastrophic. These correlations suggest in turn that the observed greater willingness of the public to accept voluntary risks may be due to these other factors and not to the voluntary nature of the activity. It appears that differences between expert and nonexpert perceptions of risk may be at least partially rooted in the different risk analysis methods and approaches used to assess and evaluate risks [ 11. Technical experts often implicitly and sometimes explicitly assign equal weight to hazards that take many lives at one time and to hazards that take many lives one at a time; nonexperts typically assign greater weight to hazards that take many lives at one time (e.g., catastrophes). Technical experts often implicitly and sometimes explicitly assign equal weight to statistical and known deaths; nonexperts typically assign greater weight to known deaths. It is interesting in this regard to note the high levels of public concern and massive allocations of resources devoted to rescuing an identifiable
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person lost at sea. Technical experts often implicitly and sometimes explicitly assign equal weight to voluntary and involuntary risks; nonexperts typically assign greater weight to involuntary risks. Technical experts typically express risks in quantitative terms and use computational and experimental methods to identify, estimate, and evaluate the risks; nonexperts typically express risks in qualitative terms and use intuitive and impressionistic methods to identify, estimate, and evaluate the risks. Technical experts typically believe that quantitative estimates of risk should be the prime consideration in risk acceptability decisions; nonexperts typically believe that quantitative estimates of risk should be only one among several quantitative and qualitative considerations in risk acceptability decisions. Technical experts often implicitly and sometimes explicitly assign the same weight to different ways of dying; nonexperts typically feel that some ways of dying are worse than others. How one dies, and with how much suffering, is as important as where and when.
Risk Perception and Nuclear Power: A Case Study TO date, most of the research on risk perception has focused on nuclear power [7, 18, 32, 35,50,58,76,80, 87, 88,90,92,93,94,101, 103, 105, 106, 108,133, 134,142, 143, 156, 1571. These studies have produced several important findings. First, researchers have shown that nuclear power has nearly all the characteristics associated with high perceived risk. The risks of nuclear power are perceived to be involuntary, delayed in their consequences, unknown, uncontrollable, unfamiliar, potentially catastrophic, inequitable, and certain to be fatal 11331. Public perceptions of nuclear power contrast sharply with nonnuclear sources of electric power, which are perceived to be noncatastrophic, familiar, controllable, and comparatively safe. Second, researchers have shown that disputes about nuclear power are often about values and goals that far transcend issues of health and safety [80, 90, 92, 100, 101, 1341. Many people are concerned about nuclear power not because of its specific risks but because of its associations with nuclear weapons, highly centralized political and economic systems, and technological elitism. The debate about nuclear power is also colored by social class-people with lower socioeconomic status are less supportive of nuclear power than those with higher socioeconomic status; by sex-women are less supportive of nuclear power than men are; and by concerns about the credibility of institutions charged with estimating, evaluating, and managing the risks [80]. Despite these concerns, research studies consistently show that the public, by a margin of 2 and sometimes 3 to 1, supports nuclear power, even in the aftermath of Three Mile Island [49, 801. Somewhat counterintuitively, researchers have also found that people living within the vicinity of a nuclear power plant (and therefore presumably subject to the greatest objective risk) are more supportive of nuclear power than those living farther away [SO]. In explaining this finding it has been proposed that people living near power plants receive greater economic benefits, that they experience greater cognitive dissonance, and that they have had their worst fears assuaged by a history of accidentfree operations. Interestingly, those who are least supportive of nuclear power live in areas where power plants are under construction or being planned. One policy implication arises from these findings. In several countries, including France, proposals are currently being considered to compensate those who live in the vicinity of nuclear power plants. If the intention is to win wider public acceptance, then the policy is misdirected. Those living nearest to the power plant are already supportive and little would be gained by compensat-
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ing them. By comparison, compensating those who are least supportive (i.e., those living in areas where power plants are under construction or being planned) might have a major impact. Such a policy of course, could also backfire by providing support for the belief that the risks of nuclear power are indeed substantial. What this specific case and others similar to it teach us is that analysts and decisionmakers need a better understanding of how people think and make decisions about technological risks. Public risk acceptance and the success of risk management policies are likely to hinge on such understanding. Stated more forcefully, without such understanding well-intended policies may be ineffective or even counterproductive. Acknowledgment This review draws heavily on the work of Paul Slavic, Baruch FischhofJ; and Sarah Lichtenstein, and I would like to acknowledge this contribution. I would also like to thank Jeryl Mumpower, Mark Abernathy, Joshua Menkes, and Jiri Nehnevajsa for their help. The views expressed in this paper are exclusively my own and do not necessarily represent the views of the National Science Foundation. References 1, Allison, A., Camesale, A., Zigman, P., and DeRosa, F., Governance of Nuclear Power, Report submitted to the President’s Nuclear Safety Oversight Committee (Sept. 1981). 2. Anderson, W., Disaster Warning and Communication Processes in Two Communities, The Journal of Communication 19 (2): 92-104 (1969). 3. Atkinson, .I. W., Motivational Determinants of Risk-Taking Behavior, Psychology Review 64: 359-372 (1957). 4. Barton,
A., Communiries in Disaster, Doubleday, New York 1970. 5. Becker, G. M., and McClintock, C. G., Value: Behavioral Decision Theory, Annual Review ofPsychology 18: 239-286
(1967).
6. Bern, D. J., Wallach,
M., and Kogan, N., Group Decision Making Under Risk of Aversive Consequences, and Social Psychology 1: 453460 (1965). Bowen, J., The Choice of Criteria for Individual Risk, for Statistical Risks, and for Public Risk, RiskBenefit Methodology and Application (UCLA-ENG-7598) D. Okrent, ed., University of California, Los Angeles, Dec. 1975. Bowman, C. H.. et al., The Prediction of Voting Behavior on a Nuclear Energy Referendum (IIASA RM-78-8), International Institute for Applied Systems Analysis Research, Laxenburg, Austria, Feb. 1978. Burton, I., and Kates, R. W., The Perception of Natural Hazard in Resource Management, Natural Resource Journal 3: 4 12-44 1 ( 1964). Burton, I., Kates, R., and White, G., The Environment as Hazard, Oxford University Press, New York, 1978. Buttel, F., and Flinn, W., The Politics of Environmental Concern: The Impacts of Party Identification and Political Ideology on Environmental Attitudes, Environment and Behavior 10: 17-35 (March 1978). Cochrane, H., Natural Hazards: Their Distributional Impacts, Monograph 14, University of Colorado, Institute of Behavioral Science, Boulder, 1975. Cole, G., and Withey, S., Perspectives on Risk Perceptions, Risk Analysis: An International Journal 1: 2 (1982). Combs, B., and Slavic, P., Causes of Death: Biased Newspaper Coverage and Biased Judgments, Journal-
Journal
7.
8.
9. 10. 11. 12. 13. 14.
of Personality
ism Quarterly 15. Craik,
56: 837-843
(1979).
K. H., Environmental Psychology, New Directions in Psychology, T. M. Newcomb, ed., Holt, Rinehart, and Winston, New York, 1970. 16. Crowe, M. J., Toward a ‘Definitional Model’ of Public Perceptions of Air Pollution, Journal of the Air Pollution Control Association 18: 154-157 (March 1968). 17. Danzig, E., Thayer, P., and Galanter, L., The Effects of a Threatening Rumor on a Disaster-Stricken Community, National Academy of Sciences, National Research Council, Washington, D.C., 1958. 18. de Boer, C., The Polls: Nuclear Energy, Public Opinion Quarterly, 402411 (Fall 1977).
292
V.T. COVELLO
19. Delcoigne, G., Education and Public Acceptance of Nuclear Power Plants, Nuclear Safety 20: 655-664 (Nov.-Dec. 1979). 20. Downs, A., Up and Down with Ecology-The Issue Attention Cycle, The Public Interest 28: 38-50 (1972). 21. Edwards, W., Behavioral Decision Theory, Annual Review of Psychology 12: 473-498 (1961). 22. Edwards, W., and Tversky, A., Decision Making, Selected Readings, Penguin Books, Middlesex, England, 1967. 23. Englemann, P. A., and Renn, O., On the Methodology of Cost-Benefit Analysis and Risk Perception, in Directions in Energy Policy, B. Kursunoglo, and A. Perlmutter, eds., Ballinger, Cambridge, Mass., 1979, pp. 357-364. 24. Falk. H., The Effect of Personal Characteristics on Attitudes Toward Risk, Journal of Risk and Insurance 43: 215-241 (June 1976). 25. Fischhoff, B., Behavioral Aspects of Cost Benefit Analysis, in Impacts and Risks of Energy Strategies: Their Analysis and Role in Management, G. Goodman, ed., Academic, London, 1979. 26. Fischhoff, B., Hindsight/Foresight: The Effect of Outcome Knowledge on Judgment Under Uncertainty, Journal of Experimental Psychology: Human Perception and Performance 1: 2X8-299 (1975). 27. Fischhoff, B., Informed Consent in Societal Risk-Benefit Decisions, Technological Forecasting and Social Change 13: 347-357 (May 1979). 28. Fischhoff, B., Slavic, P., and Lichtenstein, S., Labile Values: A Challenge for Risk Assessment, in Society, Technology and Risk Assessment, J. Conrad, ed., Academic, London, 1980, pp. 57-66. 29. Fischhoff, B., Slavic, P., Lichtenstein, S., Read, S., and Combs, B., How Safe Is Safe Enough? A Psychometric Study of Attitudes Toward Technological Risks and Benefits, Policy Sciences 9: 127-152 (1978). 30. Fishbein, M., and Azezen, I., Belief; Attitude, Intention and Behavior: An Introduction to Theory and Research, Addison-Wesley, Reading, Mass., 1975. 31. Flanders, J. P., and Thistlewaite, D. L., Effects of Familiarization and Group Discussion Upon Risk Taking, Journal of Personality and Social Psychology 5: 91-97 (1967). 32. Foreman H., ed., Nuclear Power and the Public, University of Minnesota Press, Minneapolis, 1970. 33. Friedman, M., and Savage, L. J., The Utility Analysis of Choices Involving Risks, Journal of Political Economy 56: 279-304 (1948). 34. Fritz, C., Disaster, in Corntemporary Social Problems, R. Merton and R. Nisbet, eds., Harcourt, New York, 1961, pp. 651-694. 35. Gould, L., and Walker, C. A., eds., Too Hot to Handle: Public Policy Issues in Nuclear Waste Management, Yale University Press, New Haven, Conn., 1981. 36. Green, C. H., Revealed Preference Theory: Assumptions and Presumptions, in Society, Technology and RiskAssessment, J. Conrad, ed., Academic, London, 1980, pp. 49-56. 37. Green, C. H., Risk: Attitudes and Beliefs, in Behaviour in Fires, D. V. Canter, ed., Milay, Chichester, England, 1980. 38. Green, C. H., and Brown, R. A., Counting Lives, Journal of Occupational Accidents (1978). 39. Green, C. H., and Brown, R. A., Life Safety: What Is It and How Much Is It Worth? (CP52/78), Department of the Environment, Building Research Establishment, Borehamwood, Hertfordshire, England, 1978. 40. Green, C. H., and Brown, R. A., Metrics for Societal Safety (Note N 144/78), Department of the Environment, Building Research Establishment, Borehamwood, Hertfordshire, England, 1978. 41. Green, C. H., and Brown, R. A., Perceived Safety as an Indifference Function (Note N 156178) Department of the Environment, Building Research Establishment, Borehamwood, Hertfordshire, England, 1978. 42. Green, C. H., and Brown, R. A., The Perception of; and Attitudes Towards, Risk, Final Report: Vol. 2. Measure of Safety (FR0/028/68), School of Architecture, Duncan of Jordanstone College of Art, University of Dundee, Dundee, Scotland, April 1977. 43. Green, C. H., and Brown, R. A., The Perception oJ; and Attitudes Towards, Risk, Final Report: Vol. 3. Stability of Perception under Time and Data (FR0/028/68), School of Architecture, Duncan of Jordanstone College of Art, University of Dundee, Dundee, Scotland, April 1977. 44. Green, C. H., and Brown, R. A., The Perception OJ and Attitudes Towards, Risk, Final Report: Vol. 4. Initial Experiments on Determining Satisfaction with Safety Levels (FR0/028/68), School of Architecture, Duncan of Jordanstone College of Art, University of Dundee, Dundee, Scotland, April 1977.
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293
45. Green, C. H., and Brown, R. A., Problems of Valuing Safety (Note N 70/78), Department of the Environment, Building Research Establishment, Borehamwood, Hertfordshire, England, 1978. 46. Greenberg, P. F., The Thrill Seekers, Human Behavior 6: 17-21 (April 1977). 41. Hammond, K. R., and Adleman, L., Science, Values and Human Judgment, Science 194: 389-396 (Oct. 22, 1976). 48. Harris, Louis and Associates, Inc., Harris Perspective 1979: A Survey of the Public and Environmental Activists on the Environment (59), Louis Harris and Associates, New York, 1979. 49. Harris, Louis and Associates, Inc., Risk in a Complex SocieQ, March & McClennon Public Opinion Survey, Chicago, 1980. 50. Harris, Louis and Associates, Inc., A Second Survey of Public and Leadership Attitudes Toward Nuclear Power Development in the United States, EBASCO, New York, 1976. 51. Hweitt, K., and Burton, I., The Hazardousness of a Place, University of Toronto Press, Toronto. 1971. 52. Hutton, J., and Miieti, D., Social Aspects of Earthquake, Paper presented at the Second International Conference on Microzonation, San Francisco, 1978. 53. Kahan, J. P., How Psychologists Talk About Risk (P-6403), The Rand Corporation, Santa Monica, Calif., Oct. 1979. 54. Kahneman, D., and Tversky, A., On the Psychology of Prediction, Psychological Review 80: 237-25 1 (July 1973). 55. Kahneman, D., and Tversky, A., Prospect Theory: An Analysis of Decision Under Risk, Econometrica 47: 263-291 (March 1979). 56. Kasper, R. G., Perceived Risk: Implications for Policy, Impacts and Risks of Energy Strategies: Their Analysis and Role in Management, Academic, London, 1979. 57. Kasper, R., Perceptions of Risk and Their Effects on Decision Making, in Societal Risk Assessment: How Safe Is Safe Enough:‘, R. Schwing and W. Albers, eds., Plenum, New York, 1980, pp. 71-80. 58. Kasperson, R. E., Berk, G., Pijaka, D., Sharaf, A., and Wood, J., Public Opposition to Nuclear Energy: Retrospect and Prospect, Science, Technology and Human Values 5: 1 l-23 (Spring 1980). 59. Kates, R., Human Adjustment to Earthquake Hazard, in The Great Alaska Earthquake of 1964, Committee on the Alaska Earthquake, ed., National Academy of Sciences, Washington, D.C., 1970, pp. 7-31. 60. Keeney, R. L., and Kirkwood, C. W., Group Decision Making Using Cardinal Social Welfare Functions, Management Science 22: 430-437 (1975). 61. Keeney, R. L., and Raiffa, H., Decisions with Multiple Objectives: Preferences and Value Tradeofls, Wiley, New York, 1976. 62. Klausner, S., ed., Why Man Takes Chances: Studies in Stress-Seeking, Doubleday, Garden City, N.Y., 1968. 63. Kunreuther, H., Limited Knowledge and Insurance Protection, Public Policy 24: 227-261 (1976). 64. Kunreuther, H., Ginsberg, R., Miller, L., Sagi, P., Slavic, P., Borkan, B., and Katz, N., Disaster Insurance Protection: Public Policy Lessons, Wiley, New York, 1978. 65. La Porte, T., Public Attitudes Toward Present and Future Technology, Social Studies of Science 5: 373-391 (1975). 66. La Porte, T. R., and Metlay, D.. Technology Observed: Attitudes of a Wary Public, Science 188: 121-127 (April 11, 1975). 67. La Porte, T. R., and Metlay, D., They Watch and Wonder: Public Attitudes Toward Advanced Technology, University of California, Institute of Governmental Studies, Berkeley, 1975. 68. Lerch, I., Risk and Fear, New Scientist 185: 8-l 1 (Jan. 3, 1980). 69. Lichtenstein, S., Fischhoff, B., and Phillips, L. D., Calibration of Probabilities: The State of the Art, in Decision Making and Change in Human Affairs, H. Jungermann and G. de Zeeuw, eds., Reidel, Dordrecht, 1977. 70. Lichtenstein, S., Slavic, P., Fischhoff, B.. Layman, M., and Combs, B., Judged Frequency of Lethal Events, Journal of Experimental Psychology: Human Learning and Memov 4: 551-578 (1978). 71. Linstone, H., et al., The Multipll Perspective Concept: With Applications to Technology Assessment and Other Decision Areas, Futures Research Institute, Portland State University, Portland, Oregon, 1981, See also Technological Forecasting and Social Change 20 (4): 275-325 (198 1). 72. Lowrance, W., OfAcceptable Risk, Science and the Determination of Safety, Kaufman, Los Altos, Calif., 1976. 73. Maderthaner, R., Guttman, G., Swaton, E., and Otway, H. J., Effect of Distance on Risk Perception, Journal of Applied Psychology 63 (3): 380-382 (1978).
294
V.T. COVELLO
74. Maderthaner, R., Pahner, P., Guttman, G., and Otway, H. J., Perceptions of Technological Risk: The Effect of Confrontation (IIASA RM-76-53), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1976. 75. Marquis, D. G., and Reitz, H. J., Effects of Uncertainty on Risk Taking in Individual and Group Decisions, Behavioral Science 14: 281-288 (July 1969). 76. Maynard, W. S., Nealey, S. M., Hebart, J. A., and Lindell, M. L., PublicValues Associated wirh Nuclear Waste Disposal (BNWL-1997), Battelle Human Affairs Research Center, Seattle, 1976. 77. Mazur, A., Disputes Between Experts, Minerva 11: 55-81 (1973). 78. Mazur. A., Opposition to Technological Innovation, Minerva 13: 58-81 (1975). 79. McEnvoy, J., The American Concern with the Environment, in Natural Resources and the Environment, W. R. Burch, Jr. et al., eds., Harper & Row, New York, 1972. 80. Melber. B. D., Nealey, S. M., Hammersla, .I., and Rankin, W. L., Nuclear Power and the Public: Analysis of Collected Survey Research (PNG2430), Battelle Human Affairs Research Center, Seattle, 1977. 8 1. Mileti, D., Human Adjustment to the Risk of Environmental Extremes, Sociology and Social Research 64 (3): 327-347 (April 1980). 82. Mileti, D., Natural Hazard Warning Systems in the United Stales, Monograph 13, University of Colorado, Institute of Behavioral Science, Boulder, 1975. 83. Mileti, D., Hutton, J., and Sorensen, J., Earthquake Prediction Response and Options for Public Policy, University of Colorado, Institute of Behavioral Science, Boulder, 1981. 84. Mitchell, R. C., Public Opinion on Environmental Issues: Results of a National Public Opinion Survey, Council on Environmental Quality, Department of Agriculture, Department of Energy, and Environmental Protection Agency, Washington, D.C., 1980. 85. Mitchell, R. C.. Silent Spring/Solid Majorities, Public Opinion 2 (Aug.-Sept. 1979). 86. National Academy of Sciences, A Program of Studies on the Socioeconomic Effects of Earthquake Predictions, National Academy of Sciences, National Research Council. Washington, D.C., 1978. 87. National Council on Radiation Protection and Measurements, Percepfions of Risk; Proceedings of the Fifteenth Annual Meeting, March 14-15, 1979, National Council of Radiation Protection and Measurements, Washington, D.C., March 1980. 88. Nelkin. D., Nuclear Power and Its Critics, Cornell University Press, Ithaca, N.Y., 1971. 89. Nelkin, D., The Political Impact of Technical Expertise, Social Studies ofScience 5: 35-54 (1975). 90. Nelkin, D., Some Social and Political Dimensions of Nuclear Power: Examples from Three Mile Island, American Political Science Review 75: 132-145 (March 1981). 91. Nelkin, D., Technological Decisions and Democracy, Sage Publications, Beverly Hills, Calif., 1977. 92. Nelkin, D., and Pollack, M., Political Parties and the Nuclear Energy Debate in France and Germany, Comparative Politics (Jan. 1980). 93. O’Hare, M., Not on My Block You Don’t: Facility Siting and the Strategic Importance of Compensation, Public Policy 25 (Fall 1977). 94. Okrent, D., and Whipple, C., An Approach to Societal Risk Acceptance Criteria and Risk Management (UCLA-ENG-7746). University of California, School of Engineering and Applied Science, Los Angeles, June 1977. 95. Opinion Research Corporation, Public Attitudes Toward Environmental Trade-Offs, ORC Public Opinion Index 33: l-8 (Aug. 1975). 96. Otway, H. J., The Perception of Technological Risks: A Psychological Perspective, in Technological Risk: Its Perception and Handling in the European Community, M. Dierkes, S. Edwards. and R. Coppock, eds., Oelgeschlager, Gunn and Hain, Cambridge, Mass., 1980, pp. 34-45. 97. Otway. H. J., Risk Assessment and Societal Choices (IIASA RM-75-2), International Institute for Applied Systems Analysis, Laxenburg, Austria, Feb. 1975. 98. Otway, H. J.. et al., On the Social Aspects of Risk Assessment, Journal of the Society for Industrial and Applied Mathematics (1977). 99. Otway. H. J., and Cohen, J. J., Revealed Pwferences: Comments on the Starr Benefit-Risk Relationships (IIASA RM-75-5), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1975. 100. Otway, H. J., and Fishbein, M., Public Attitudes and Decision Making (IIASA RM-77-54). International Institute for Applied Systems Analysis, Laxenburg, Austria, 1977. 101. Otway, H. J., and Fishbein, M., The Determinants of Attitude Formation: An Application to Nuclear Power (IIASA RM-7&80), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1976.
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OF TECHNOLOGICAL
RISKS
295
102. Otway, H. J., Maderthaner, R., and Gunman, G., Avoidance Response to the Risk Environment: A CrossCultural Comparison (IIASA RM-75-14), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1975. 103. Otway, H. J., Maurer, D., and Thomas, K., Nuclear Power, The Question of Public Acceptance, Futures 10: 109-l 18 (April 1978). 104. Otway, H. J., Pahner, P. D., and Linnerooth, J., Social V&es in Risk Acceptance (IIASA RM-7%54), International Institute for Applied Systems Analysis, Laxenburg, Austria, Nov. 1975. 105. Pahner, P. D., The Psychological Displacement of Anxiety: An Application to Nuclear Power, in RiskBenefit Methodology and Application (UCLA-ENG-7598). D. Okrent, ed., University of California, Los Angeles, Dec. 1975. 106. Pahner, P. D., A Psychological Perspective of the Nuclear Energy Controversy (IIASA RM-76-67), International Institute for Applied System Analysis, Laxenburg, Austria, 1976. 107. Payne, J. W., Relation of Perceived Risk to Preferences Among Gamblers, Journal of Experimental Psychology: Human Perception and Performance 104: 86-94 (1975). 108. Pearce, D. W., The Nuclear Power Debate Is About Values, Nature 274: 200 (1978). 109. Pearce, D. W., The Preconditions for Achieving Consensus in the Context of Technological Risk, in Technological Risk: Its Perception and Handling in the European Community, M. Dierkes, S. Edwards, and R. Coppock, eds., Oelgeschlager, Gunn and Hain, Cambridge, Mass., 1980. 110. Powers, W. T., Behavior: The Control of Perception, Aldine, Chicago, 1973. 111. Pratt, J. W., Raiffa, H., and Schlaifer, R., The Foundations of Decision Under Uncertainty, The American Statistical Association
Journal
59: 353-376
(1964).
112. Raiffa, H., Decision Analysis: Introductory Lectures on Choices Under Uncertainty, Addison-Wesley, Reading, Mass., 1968. 113. Rapoport, A., and Wallsten, T. S., Individual Decision Behavior, Annual Review of Psychology 23: 131-175
(1972).
114. Ravetz, J. R., Public Perceptions of Acceptable Risks as Evidence for Their Cognitive, Technical, and Social Structure, in Technological Risk: Its Perception and Handling in the European Community, M. Dierkes, S. Edwards, and R. Coppock, eds., Oelgeschlager, Gunn, and Hain, Cambridge, Mass. 1980, pp. 46-57. 115. Rethans, A., An Investigation of Consumer Perceptions of Product Hazards, Unpublished Ph.D. dissertation, University of Oregon, 1979. 116. Ross, L., The Intuitive Psychologist and His Shortcomings, in Advances in Social Psychology, L. Berkowitz, ed., Academic, New York, 1977. 117. Rowe, W. E., An Anatomy of Risk, Wiley, New York, 1977. 118. Sapolsky, H. M., Science, Voters, and the Fluoridation Controversy, Science 162: 427-433 (1958). 1 19. Sjoberg, L., Risk Generation and Risk Assessment in a Social Perspective, Foresight, the Journal of Risk Management
3: 4-12
(1978).
120.
Sjoberg, L., Strength of Belief and Risk, Policy Sciences 2: 39-52 (Aug. 1979). 121. Slavic, P., Assessment of Risk-Taking Behavior, Psychological Bulletin 61: 220-233 (1964). 122. Slavic, P., Choice Between Equally Valued Alternatives, Journal of Experimental Psychology: Human Perception and Performance 1: 28&287 (1975). 123. Slavic, P., and Fischhoff, B., Cognitive Process and Societal Risk Taking, in Cognition and Sociefal Behavior, J. S. Carroll and J. W. Payne, eds., Lawrence Erlbaum Associates, Potomac, Md., 1976. 124. Slavic, P., Fischhoff, B., and Lichtenstein, S., Accident Probabilities and Seat Belt Usage: A Psychological Perspective, Accident Analysis and Prevention 10: 281-285 (1978). 125. Slavic, P., Fischhoff, B., and Lichtenstein, S., Behavioral Decision Theory, Annual Review of Psychology 28: l-39
(1977).
P., Fischhoff, B., and Lichtenstein, S., Characterizing Perceived Risk, in Technological Hazard Management, R. W. Kates and C. Hohenemser, eds, Oelgeschlager, Gunn and Hain, Cambridge, Mass., 1981. 127. Slavic, P., Fischhoff, B., and Lichtenstein, S.. Facts and Fears: Understanding Perceived Risk, in Societal Risk Assessment: How Safe Is Safe Enough?, R. Schwing and W. Albers, Jr., eds., Plenum, New York, 1980, pp. 181-216. 128. Slavic, P., Fischhoff, B., and Lichtenstein, S., Informing People about Risk, in Product Labeling and Health Risks (Banbury Report 6), L. Morris, M. Maris, and I. Barofsky, eds., Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., 1980. 129. Slavic, P., Fischhoff, B., and Lichtenstein, S., Rating the Risks, Environment 21 (3): 14-39 (April 1979). 126. Slavic,
296
V.T. COVELLO
130. Slavic, P., Fischhoff, B., and Lichtenstein, S., Risky Assumptions, Psychology Today 14: 44-45, 47-48 (June 1980). 13 1. Slavic, P., Fischhoff, B., Lichtenstein, S., Corrigan, B., and Combs, B., Preference for Insuring Against Probable Small Losses: Insurance Implications, Journal of Risk and Insurance 45: 237-258 (June 1977). 132. Slavic, P., Kunreuther, H., and White, Cl., Decision Processes, Rationality and Adjustments to Natural Hazards, in Natural Hazurds: Local, National, and Global, G. F. White, ed., Oxford University Press, New York, 1974. 133. Slavic, P., Lichtenstein, S., and Fischhoff, B., Images of Disaster: Perception and Acceptance of Risks from Nuclear Power, in Energy Risk Management, G. Goodman and W. Rowe, eds., Academic. London, 1979. 134. Spangler. M. B., Risks and Psychic Costs of Alternative Energy Sources for Generating Electricity, The Energy Journal (Jan. 1981). 135. Starr, C., Social Benefit versus Technological Risk, Science 165: 1232-1238 (Sept. 19, 1969). 136. Starr, C., Some Comments on the Public Perception of Personal Risk and Benefit, in Risk vs. Benefit: Solution or Dream? H. J. Otway, ed., Los Alamos National Laboratory, Los Alamos, N.M., 1971. 137. Starr, C., and Whipple, C., Risk of Risk Decisions, Science 208: 1114-l 119 (June 1980). 138. Stumpf, S. E., Culture, Values, and Food Safety, BioScience 28: 186-190 (March 1978). 139. Svenson, O., Are We All Among the Better Drivers?, Unpublished report, Department of Psychology, University of Stockholm, Stockholm, Sweden, 1979. 140. Swaton, E., Maderthaner, R., Pahner, P. D., Guttman, G., and Otway, H. J., The Determinants of Risk Perception: A Survey (IIASA RM-76Xx), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1976. 141. Tamerin, T., and Resnick, L. P., Risk Taking by Individual Option--Case Study: Cigarette Smoking, Perspectives on Benefit-Risk Decision Making, National Academy of Engineering, Washington, D.C., 1972. pp. 73-84. 142. Thomas, K., Maurer, D., Fishbein, M., Otway, H., Hinkle, R., and Simpson, D., A Comparative Study of Public Beliefs About Five Energy Systems (IIASA RR-Et&l), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1979. 143. Thomas, K., Swaton, E., Fishbein, M., and Otway, H., Nuclear Energy: The Accuracy of Policy Makers’ Perceptions of Public Beliefs (IIASA RR-E&2), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1979. 144. Thompson, M., Aesthetics of Risk: Context or Culture’?, in Societal Risk Assessment: How Safe Is Safe Enough?, R. Schwing and W. Albers, eds., Plenum, New York, 1980, pp. 273-286. 145. Thomgate. W., Efficient Decision Heuristics, Behavioral Science 25: 219-225 (1980). 146. Tubiana, M., One Approach to the Study of Public Acceptance, in Directions in Energy Policy, B. Kursunoglu and A. Perlmutter, eds., Ballinger, Cambridge, Mass., 1979. 147. Tversky, A., Elimination by Aspects: A Theory of Choice, Psychological Review 79: 281-299 (1972). 148. Tversky, A., and Kahneman, D., The Framing of Decisions and the Psychology of Choice, Science 211: 1453-1458 (1981). 149. Tversky, A., and Kahneman, D., Availability: A Heuristic for Judging Frequency and Probability, Cognitive Psychology 4: 207-232 (1973). 150. Tversky, A., and Kahneman, D., Judgment Under Uncertainty: Heuristics and Biases, Science 185: 1124-l 131 (Sept. 27, 1974). 151. Tversky, A., and Sattath, S., Preferences Trees, Psychological Review 86: 542-573 (1979). 152. Velimirovic. H., An Anthropological View of Risk Phenomena (IIASA RM-75-Xx), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1975. 153. Vlek, C., and Stallen, P. J., Judging Risks and Benefits in the Small and in the Large, Organizational Behavior and Human Performance 38 (Oct. 1981). 154. Vlek, C., and Stallen, P. J., Rational and Personal Aspects of Risk, Acta Psychologica 45 (1980). 155. Von Neuman, J., and Morgenstem, 0.. Theory of Games and Economic Behavior, Princeton University Press, Princeton, N.J., 1944. 156. Von Winterfeldt, D., Edwards, W., Anson, J., Stillwell, W., and Slavic, P., Development of a Methodology IO Evaluate Risks from Nuclear Electric Power Plants: Phase I-IdentifLinR Social Groups and Structuring Their Values and Concerns, Final Report to Sandia National Laboratories, Albuquerque, N.M., May 1980. 157. Von Winterfeldt, D., and Rios, M., Conflicts about Nuclear Power Safety: A Decision Theoretic Approach, in Proceedings of the ANSIENS Topical Meeting on Thermal Reactor Safety. M. H. Fontana and D. R. Patterson, eds., National Technical Information Service, Springfield, Va., 1980, pp. 696709.
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OF TECHNOLOGICAL
RISKS
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158. Weinstein, N. D., It Won’t Happen to Me: Cognitive and Motivational Sources of Unrealistic Optimism, Unpublished paper, Department of Psychology, Rutgers University, 1979. 159. Wendt, D., and Vlek, C., eds., Subjective Probability, Utility and Human Decision Making, Reidel, Dordrecht, 1974. 160. White, A., Global Summary of Human Responses to Natural Hazards: Tropical Cyclones, in Natural Hazards: Local, National, Global, G. White, ed., Oxford University Press, New York, 1974. 161. White, G., ed., Natural Hazards: Local, National, Global, Oxford University Press, New York, 1974. 162. White, G., Choice of Adjustments to Flood, Research paper no. 93, University of Chicago, Department of Geography, Chicago, 1964. 163. White, G., and Haas, J., Assessment of Research on Natural Hazards, MIT press, Cambridge, Mass., 1975. 164. White, G. F., Formation and Role of Public Attitudes, in Environmental Quality in a Growing Economy, H. Jarret, ed., Johns Hopkins University Press, Baltimore, 1966. 165. White, G. F., Human Responses to Natural Hazard, Perspectives on Benefit-Risk Decision Making, National Academy of Engineering, Committee on Public Engineering Policy, Washington, D.C., 1972. 166. Zebroski, E. L., Attainment of Balance in Risk-Benefit Perceptions, in Risk-Benefit Methodology and Application. Some Papers Presented at the Foundation Workshop, Asilomar, California (UCLA-ENG-7598), D. Okrent, ed., University of California, Los Angeles, 1975. Received 26 July 1982
FORECASTING
AND SOCIAL CHANGE
23, 285-297
(1983)
The Perception of Technological Risks: A Literature Review VINCENT T. COVELLO
ABSTRACT
In response to rising concern about technological risks, a concerted effort is being made to improve risk analysis methods and risk management approaches. As part of this effort, behavioral and social scientists have produced a substantial body of knowledge of value to risk analysts and decision makers. This paper focuses on behavioral and social science studies of human intellectual limitations in thinking about risks, factors influencing risk attitudes and perceptions, and factors contributing to social conflicts and disputes about technological activities. A basic assumption of the paper is that analysts and decision makers can benefit from a better understanding of how experts and nonexperts think and make decisions about technological risks. Without such understanding, well-intended policies may be ineffective or even counterproductive.
Introduction A truly unexpected result came out of the Kemeny Commission’s study of Three Mile Island. A group that set out to investigate a technology ended up talking about people. . . . In the commission’s own words, “It became clear that the fundamental problems were people-related problems.” Editorial,
Washington Post, October 31, 1979.
Behavorial and social scientists in several countries are currently grappling with several people-related questions related to risk: What factors influence individual perceptions of risk? What accounts for anomalies in the way individuals and groups behave when faced with ostensibly comparable risks-such as the risks of nuclear power, dam failures, or earthquakes? What weight should decision makers attach to public perceptions of risk in determining how safe is safe enough? Are there ways to increase our capacity for dealing with technological risks in a rational manner? What follows is a review of the behavioral and social science literature pertaining to these questions (See [l] through [166]). Before beginning, however, several points need to be made concerning the quality of the data and the research. First, most of the reported findings are based on surveys of small, highly specialized, and unrepresentative groups. An important set of risk perception studies undertaken by Paul Slavic and his colleagues,
VINCENT COVELLO is Program Manager for Risk Analysis Research at the National Science Foundation, Washington, D.C. Address reprint request to Dr. Vincent T. Covello, National Science Foundation, 1800 G St., NW, Washington, D.C. 20550. 0 1983 by Elsevier Science Publishing
Co, Inc.
0040-1625/83/$03.00
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for example, relied almost entirely on data gathered from residents of Eugene, Oregon, a small university town located in a state with a high level of environmental concern and a progressive environmental protection program [29, 127, 1291. The respondents included 40 members of the Eugene League of Women Voters, 40 college students at the University of Oregon, 25 Eugene business people, and 1.5 persons selected nationwide for their expertise in risk analysis. Second, little attempt has been made by researchers to analyze the effects of organizational and social structural variables (e.g., ethnicity, religion, sex, region of the country, age group, occupation, education, income, marital status, organizational membership, and organizational location) on risk perceptions. Most studies adopt a personal or technical perspective [71] and start from the assumption that individual risk perceptions can be explained by the psychological makeup of the individual or by the degree to which the individual has access to, and correctly interprets, technical information. With relatively few exceptions, researchers have not adopted an organizational or social structural perspective, which assumes that risk perceptions are substantially influenced by group norms and expectations, and by the social and organizational location of the individual. As Linstone [71] has shown, studies that ignore or unduly emphasize one of these three perspectives-personal, technical, or organizational-are considerably less useful than studies that attempt an integrated analysis. Unfortunately, risk perception research is still at an early stage of development, and this integration has not yet occurred. Third, the risk perception literature suffers, in an exaggerated form, from shortcomings common to nearly all survey research [28]: (1) people typically respond to survey questions with the first thing that comes to mind, and then become committed to their answer; (2) people typically provide an answer to any question that is posed, even when they have no opinion, when they do not understand the question, or when they hold inconsistent beliefs; (3) survey responses can be influenced by the order in which the questions are posed, by whether the emphasis in on speed or accuracy, by whether the question is closed or open, by whether respondents are asked for a verbal or numerical answer, by interviewer prompting, and by how the question is posed. Risk perception surveys are especially vulnerable to these types of biases, because people are often unfamiliar with the activity or substance being assessed and because they may not understand the technical and methodological issues under debate. Fourth, although risk perceptions may be inconsistent with behavior, relatively few studies have examined the relationship between perceptions of technological hazards and the behavior of people in actual situations. Empirical studies from other social and behavioral fields suggest that the linkages between perception and behavior are highly complex and appear to be mediated by several factors [6, 13, 621. Researchers have shown, for example, that activist behavior is related to a willingness to participate in group activities, a positive identification with potential group leaders, a belief in the efficacy of social action, and physical proximity to arenas of social conflict [13, 301. With few exceptions [78, 901, risk perception researchers have not examined these variables. Fifth, for reasons that are not entirely clear, researchers have made few attempts to relate the literature on the perceived risks of technological hazards to the extensive literature on the perceived risks of natural disasters [2, 3, 4, 9, 10, 12, 17, 34, 51, 52, 39, 64, 71, 81, 82, 83, 861. To date, only limited efforts have been made to replicate and extend natural hazard studies concerned with the various factors that affect perceived risks, including the perceived cause of the disaster, the degree to which risk information is available and accessible, the form in which risk information is presented, the institutional
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and social location of the individual evaluating the risk, the individual’s previous disaster experiences, and the perceived level of hazard protection and security. Furthermore, only limited efforts have been made to replicate or extend natural hazard studies concerned with the various factors that mediate between perceived risk and actual behavior, including the perceived benefits of risk mitigation actions, the presence or absence of evidence validating or confirming the threat, and the individual’s mental image of potential damages. Finally, the findings reported in this paper are confounded by several unresolved problems: risk perceptions may change rapidly; people may not understand how their perceptions and preferences translate into policy; and people may prefer alternatives not realistically obtainable. With these reservations and qualifications in mind, some of the major findings of risk perception literature are discussed below. Human Intellectual Limitations Research suggests that people do not cope well when confronted with risk problems and decisions. Intellectual limitations and the need to reduce anxiety often lead to the denial that risk and uncertainty exist and to unrealistic oversimplifications of essentially complex problems [120, 127, 1501. To simplify risk problems, people use a number of inferential or judgmental rules, known technically as heuristics [54, 55, 147, 148, 149, 1501. Two of the most important are 1) information availability, or the tendency for people to judge an event more frequent if instances of it are easy to imagine or recall; and 2) representativeness, or the tendency of people to assume that roughly similar activities and events (such as nuclear power technologies and nuclear war) have the same characteristics and risks. These judgmental operations enable people to reduce difficult probabilistic and assessment tasks to simpler tasks; however, these judgmental operations also lead to severe and systematic biases and errors. One bias associated with information availability is that people have difficulty imagining low probability/high consequence events happening to themselves [9, 120, 1271. Unless people have been made graphically aware of the risks, typically through past experience, they are unlikely to take protective action [63, 64, 1651. A classic example is the observed reluctance of floodplain residents to purchase low-cost flood insurance [64]. Compounding the problem is the difficulty people have understanding and interpreting probabilistic information. People residing in loo-year floodplains, for example, typically believe that a recent severe flood precludes the possibility of another severe flood in the near future [9, 1651. According to folk wisdom but not to probability theory, lightning never strikes the same place twice. Biases associated with information availability have also been used to explain the results of studies in which people were asked to judge the frequency of various causes of death, such as accidents, tornadoes, and diseases [127]. These studies show that the risks of low-frequency events tend to be overestimated, and that the risks of high-frequency events are underestimated. People underestimate fatalities caused by asthma, stroke, and diabetes, and overestimate fatalities from homicides, botulism, fires, snake bites, tornadoes, and abortion. Overestimated causes of death tend to be dramatic, sensational, and of interest to the media, whereas underestimated causes of death tend to be unspectacular, undramatic, and of little interest to the media [14, 1271. Researchers have also pointed out that information availability biases may cause risk information campaigns and educational efforts to work at cross-purposes [ 1331. Information may heighten the imaginability and consequently the perceived probability of a rare
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event, even when the information is designed to assure individuals that the event is unlikely. A package insert listing all the risks of taking a drug, or a published report describing safety precautions taken at a DNA research laboratory, may serve only to increase concern about the substance or activity. By identifying previously unknown ways in which things can go wrong, the information provider takes the chance that people will incorrectly assess the information (i.e., that they will consider the event more likely as a result of increased knowlege). As one observer notes [77, p. 611: We generally assume that informed advice is valuable to political policy-makers. However, in the context of a controversial political issue, and when the relevant technical analysis is ambiguous, then the value of scientific advice become questionable. A technical controversy sometimes creates confusion rather than clarity, and it is possible that the dispute itself may become so divisive and widespread that scientific advice becomes more of a cost than a benefit to the policy-maker and society.
Unfortunately, few researchers have critically examined the controversial hypothesis implicit in this work-that the very discussion of a low-probability hazard increases the judged probability of the hazard, regardless of what the evidence indicates. Disputes and controversies about risk are made all the more difficult by another psychological mechanism: once beliefs are formed, individuals frequently structure and distort the interpretation of new evidence and often resist disconfirming information [116, 1271. People tend to dismiss evidence contradicting their beliefs as unreliable, erroneous, and unrepresentative. The accident at Three Mile Island, for example, provided confirming evidence for those already convinced that nuclear power technology is safe [90]; the accident also reinforced the beliefs of those who believed that nuclear power technology is dangerous. Convincing people that a hazard they fear is not a hazard is extremely difficult even under the best conditions. Any accident or mishap, no matter how small, is seen as proof of high risk [133]. Overconfidence Another second set of risk perception findings addresses the problem of overconfidence. Researchers have shown that experts and laypersons are typically overconfident about their risk estimates. In one study participants were asked to state the odds that they were correct in judging which of two lethal events was the more frequent [127]. Most people claimed that the odds of their -being wrong were 1OO:l or greater. In actuality, people were wrong about one out of every eight times. Such overconfidence can produce serious judgmental errors, including judgments about how much is known about the hazard and about how much needs to be known. Of equal or greater importance, overconfidence leads people to believe that they are comparatively immune to common hazards. Studies show that 1) most people rate themselves among the most skillful and safe drivers in the population; 2) people rate their own personal risk from several common household hazards as lower than the risk for others in society; 3) people judge themselves average or above average in their ability to avoid bicycle and power lawnmower accidents; and 4) people underestimate and are extremely unrealistic about their chances of having a heart attack (115, 139, 1581. In general, people underestimate the risks of activities that they perceive to be familiar and under their personal control, such as automobile driving. Overconfidence has also been used to explain in part the observed reluctance of about 80 to 90% of the U.S. driving population to wear seat belts [124]. Unfortunately, few empirical studies have examined this issue or the more general relationship between perceived risk and protective behavior. One new study by Slavic, Lichtenstein, and
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Fischhoff of seat belt usage is, however, exploring and empirically testing the hypothesis that seat belt usage will increase if the public is presented with information about the lifetime risks of driving instead of information about the risks of taking a single trip. Expert and Nonexpert Estimates of Risk A third set of findings bears on expert and nonexpert estimates of risk. A consistent result is that technical experts and nonexperts differ substantially in their risk estimates [57]. Risk estimates of technical experts are closely correlated with annual fatality rates, whereas the risk estimates of nonexperts are only moderately to poorly correlated with annual fatality rates [ 1291. In explaining these differences, researchers have identified several factors other than annual fatality rates that influence public perceptions of risk [72, 127, 153, 1541. Risks are perceived to be higher if the activity is perceived to be involuntary, catastrophic, not personally controllable, inequitable in the distribution of its risk and benefits, unfamiliar, and highly complex. Other factors influencing risk perceptions are whether the adverse effects are immediate or delayed, whether exposure to the hazard is continuous or occasional, whether the technology is perceived to be necessary or luxury, whether the adverse effects are well-known or uncertain, and whether the activity is certain to be fatal. Several studies have shown that these dimensions of risk are closely related to each other [ 126, 153, 1541. Such correlations have prompted several research groups to reduce the various dimensions of risk to a smaller number of factors. One study identified at least two factors [29]: the level of technological complexity and the hazard’s severity or catastrophic potential. In a follow-up study that examined a larger set of hazards and risk characteristics, Slavic, Fischhoff, and Lichtenstein [ 1271 found three factors: familiarity, dread, and the number of people exposed to the hazard. In an ongoing European study of risk perception, Vlek and Stallen identified several additional factors influencing risk perception and risk acceptability, including the beneficiality of the technology and the degree to which protection is provided by institutional means [ 153, 1541. In spite of these different findings, it is clear that a hazard’s catastrophic potential is uppermost in the minds of people. Because catastrophic events may threaten the survival of individuals, families, societies, and the species as a whole, such concern may be quite justifiable. Analysis of intercorrelations between the various dimensions of risk have also led researchers to challenge Starr’s [135] well-known proposition that the risks of voluntary activities are more acceptable to the general public than the risks of involuntary activities [5, 99, 1271. One problem with this proposition is that voluntary risks are also perceived by the public to be controllable, equitable, familiar, and noncatastrophic. These correlations suggest in turn that the observed greater willingness of the public to accept voluntary risks may be due to these other factors and not to the voluntary nature of the activity. It appears that differences between expert and nonexpert perceptions of risk may be at least partially rooted in the different risk analysis methods and approaches used to assess and evaluate risks [ 11. Technical experts often implicitly and sometimes explicitly assign equal weight to hazards that take many lives at one time and to hazards that take many lives one at a time; nonexperts typically assign greater weight to hazards that take many lives at one time (e.g., catastrophes). Technical experts often implicitly and sometimes explicitly assign equal weight to statistical and known deaths; nonexperts typically assign greater weight to known deaths. It is interesting in this regard to note the high levels of public concern and massive allocations of resources devoted to rescuing an identifiable
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person lost at sea. Technical experts often implicitly and sometimes explicitly assign equal weight to voluntary and involuntary risks; nonexperts typically assign greater weight to involuntary risks. Technical experts typically express risks in quantitative terms and use computational and experimental methods to identify, estimate, and evaluate the risks; nonexperts typically express risks in qualitative terms and use intuitive and impressionistic methods to identify, estimate, and evaluate the risks. Technical experts typically believe that quantitative estimates of risk should be the prime consideration in risk acceptability decisions; nonexperts typically believe that quantitative estimates of risk should be only one among several quantitative and qualitative considerations in risk acceptability decisions. Technical experts often implicitly and sometimes explicitly assign the same weight to different ways of dying; nonexperts typically feel that some ways of dying are worse than others. How one dies, and with how much suffering, is as important as where and when.
Risk Perception and Nuclear Power: A Case Study TO date, most of the research on risk perception has focused on nuclear power [7, 18, 32, 35,50,58,76,80, 87, 88,90,92,93,94,101, 103, 105, 106, 108,133, 134,142, 143, 156, 1571. These studies have produced several important findings. First, researchers have shown that nuclear power has nearly all the characteristics associated with high perceived risk. The risks of nuclear power are perceived to be involuntary, delayed in their consequences, unknown, uncontrollable, unfamiliar, potentially catastrophic, inequitable, and certain to be fatal 11331. Public perceptions of nuclear power contrast sharply with nonnuclear sources of electric power, which are perceived to be noncatastrophic, familiar, controllable, and comparatively safe. Second, researchers have shown that disputes about nuclear power are often about values and goals that far transcend issues of health and safety [80, 90, 92, 100, 101, 1341. Many people are concerned about nuclear power not because of its specific risks but because of its associations with nuclear weapons, highly centralized political and economic systems, and technological elitism. The debate about nuclear power is also colored by social class-people with lower socioeconomic status are less supportive of nuclear power than those with higher socioeconomic status; by sex-women are less supportive of nuclear power than men are; and by concerns about the credibility of institutions charged with estimating, evaluating, and managing the risks [80]. Despite these concerns, research studies consistently show that the public, by a margin of 2 and sometimes 3 to 1, supports nuclear power, even in the aftermath of Three Mile Island [49, 801. Somewhat counterintuitively, researchers have also found that people living within the vicinity of a nuclear power plant (and therefore presumably subject to the greatest objective risk) are more supportive of nuclear power than those living farther away [SO]. In explaining this finding it has been proposed that people living near power plants receive greater economic benefits, that they experience greater cognitive dissonance, and that they have had their worst fears assuaged by a history of accidentfree operations. Interestingly, those who are least supportive of nuclear power live in areas where power plants are under construction or being planned. One policy implication arises from these findings. In several countries, including France, proposals are currently being considered to compensate those who live in the vicinity of nuclear power plants. If the intention is to win wider public acceptance, then the policy is misdirected. Those living nearest to the power plant are already supportive and little would be gained by compensat-
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ing them. By comparison, compensating those who are least supportive (i.e., those living in areas where power plants are under construction or being planned) might have a major impact. Such a policy of course, could also backfire by providing support for the belief that the risks of nuclear power are indeed substantial. What this specific case and others similar to it teach us is that analysts and decisionmakers need a better understanding of how people think and make decisions about technological risks. Public risk acceptance and the success of risk management policies are likely to hinge on such understanding. Stated more forcefully, without such understanding well-intended policies may be ineffective or even counterproductive. Acknowledgment This review draws heavily on the work of Paul Slavic, Baruch FischhofJ; and Sarah Lichtenstein, and I would like to acknowledge this contribution. I would also like to thank Jeryl Mumpower, Mark Abernathy, Joshua Menkes, and Jiri Nehnevajsa for their help. The views expressed in this paper are exclusively my own and do not necessarily represent the views of the National Science Foundation. References 1, Allison, A., Camesale, A., Zigman, P., and DeRosa, F., Governance of Nuclear Power, Report submitted to the President’s Nuclear Safety Oversight Committee (Sept. 1981). 2. Anderson, W., Disaster Warning and Communication Processes in Two Communities, The Journal of Communication 19 (2): 92-104 (1969). 3. Atkinson, .I. W., Motivational Determinants of Risk-Taking Behavior, Psychology Review 64: 359-372 (1957). 4. Barton,
A., Communiries in Disaster, Doubleday, New York 1970. 5. Becker, G. M., and McClintock, C. G., Value: Behavioral Decision Theory, Annual Review ofPsychology 18: 239-286
(1967).
6. Bern, D. J., Wallach,
M., and Kogan, N., Group Decision Making Under Risk of Aversive Consequences, and Social Psychology 1: 453460 (1965). Bowen, J., The Choice of Criteria for Individual Risk, for Statistical Risks, and for Public Risk, RiskBenefit Methodology and Application (UCLA-ENG-7598) D. Okrent, ed., University of California, Los Angeles, Dec. 1975. Bowman, C. H.. et al., The Prediction of Voting Behavior on a Nuclear Energy Referendum (IIASA RM-78-8), International Institute for Applied Systems Analysis Research, Laxenburg, Austria, Feb. 1978. Burton, I., and Kates, R. W., The Perception of Natural Hazard in Resource Management, Natural Resource Journal 3: 4 12-44 1 ( 1964). Burton, I., Kates, R., and White, G., The Environment as Hazard, Oxford University Press, New York, 1978. Buttel, F., and Flinn, W., The Politics of Environmental Concern: The Impacts of Party Identification and Political Ideology on Environmental Attitudes, Environment and Behavior 10: 17-35 (March 1978). Cochrane, H., Natural Hazards: Their Distributional Impacts, Monograph 14, University of Colorado, Institute of Behavioral Science, Boulder, 1975. Cole, G., and Withey, S., Perspectives on Risk Perceptions, Risk Analysis: An International Journal 1: 2 (1982). Combs, B., and Slavic, P., Causes of Death: Biased Newspaper Coverage and Biased Judgments, Journal-
Journal
7.
8.
9. 10. 11. 12. 13. 14.
of Personality
ism Quarterly 15. Craik,
56: 837-843
(1979).
K. H., Environmental Psychology, New Directions in Psychology, T. M. Newcomb, ed., Holt, Rinehart, and Winston, New York, 1970. 16. Crowe, M. J., Toward a ‘Definitional Model’ of Public Perceptions of Air Pollution, Journal of the Air Pollution Control Association 18: 154-157 (March 1968). 17. Danzig, E., Thayer, P., and Galanter, L., The Effects of a Threatening Rumor on a Disaster-Stricken Community, National Academy of Sciences, National Research Council, Washington, D.C., 1958. 18. de Boer, C., The Polls: Nuclear Energy, Public Opinion Quarterly, 402411 (Fall 1977).
292
V.T. COVELLO
19. Delcoigne, G., Education and Public Acceptance of Nuclear Power Plants, Nuclear Safety 20: 655-664 (Nov.-Dec. 1979). 20. Downs, A., Up and Down with Ecology-The Issue Attention Cycle, The Public Interest 28: 38-50 (1972). 21. Edwards, W., Behavioral Decision Theory, Annual Review of Psychology 12: 473-498 (1961). 22. Edwards, W., and Tversky, A., Decision Making, Selected Readings, Penguin Books, Middlesex, England, 1967. 23. Englemann, P. A., and Renn, O., On the Methodology of Cost-Benefit Analysis and Risk Perception, in Directions in Energy Policy, B. Kursunoglo, and A. Perlmutter, eds., Ballinger, Cambridge, Mass., 1979, pp. 357-364. 24. Falk. H., The Effect of Personal Characteristics on Attitudes Toward Risk, Journal of Risk and Insurance 43: 215-241 (June 1976). 25. Fischhoff, B., Behavioral Aspects of Cost Benefit Analysis, in Impacts and Risks of Energy Strategies: Their Analysis and Role in Management, G. Goodman, ed., Academic, London, 1979. 26. Fischhoff, B., Hindsight/Foresight: The Effect of Outcome Knowledge on Judgment Under Uncertainty, Journal of Experimental Psychology: Human Perception and Performance 1: 2X8-299 (1975). 27. Fischhoff, B., Informed Consent in Societal Risk-Benefit Decisions, Technological Forecasting and Social Change 13: 347-357 (May 1979). 28. Fischhoff, B., Slavic, P., and Lichtenstein, S., Labile Values: A Challenge for Risk Assessment, in Society, Technology and Risk Assessment, J. Conrad, ed., Academic, London, 1980, pp. 57-66. 29. Fischhoff, B., Slavic, P., Lichtenstein, S., Read, S., and Combs, B., How Safe Is Safe Enough? A Psychometric Study of Attitudes Toward Technological Risks and Benefits, Policy Sciences 9: 127-152 (1978). 30. Fishbein, M., and Azezen, I., Belief; Attitude, Intention and Behavior: An Introduction to Theory and Research, Addison-Wesley, Reading, Mass., 1975. 31. Flanders, J. P., and Thistlewaite, D. L., Effects of Familiarization and Group Discussion Upon Risk Taking, Journal of Personality and Social Psychology 5: 91-97 (1967). 32. Foreman H., ed., Nuclear Power and the Public, University of Minnesota Press, Minneapolis, 1970. 33. Friedman, M., and Savage, L. J., The Utility Analysis of Choices Involving Risks, Journal of Political Economy 56: 279-304 (1948). 34. Fritz, C., Disaster, in Corntemporary Social Problems, R. Merton and R. Nisbet, eds., Harcourt, New York, 1961, pp. 651-694. 35. Gould, L., and Walker, C. A., eds., Too Hot to Handle: Public Policy Issues in Nuclear Waste Management, Yale University Press, New Haven, Conn., 1981. 36. Green, C. H., Revealed Preference Theory: Assumptions and Presumptions, in Society, Technology and RiskAssessment, J. Conrad, ed., Academic, London, 1980, pp. 49-56. 37. Green, C. H., Risk: Attitudes and Beliefs, in Behaviour in Fires, D. V. Canter, ed., Milay, Chichester, England, 1980. 38. Green, C. H., and Brown, R. A., Counting Lives, Journal of Occupational Accidents (1978). 39. Green, C. H., and Brown, R. A., Life Safety: What Is It and How Much Is It Worth? (CP52/78), Department of the Environment, Building Research Establishment, Borehamwood, Hertfordshire, England, 1978. 40. Green, C. H., and Brown, R. A., Metrics for Societal Safety (Note N 144/78), Department of the Environment, Building Research Establishment, Borehamwood, Hertfordshire, England, 1978. 41. Green, C. H., and Brown, R. A., Perceived Safety as an Indifference Function (Note N 156178) Department of the Environment, Building Research Establishment, Borehamwood, Hertfordshire, England, 1978. 42. Green, C. H., and Brown, R. A., The Perception of; and Attitudes Towards, Risk, Final Report: Vol. 2. Measure of Safety (FR0/028/68), School of Architecture, Duncan of Jordanstone College of Art, University of Dundee, Dundee, Scotland, April 1977. 43. Green, C. H., and Brown, R. A., The Perception oJ; and Attitudes Towards, Risk, Final Report: Vol. 3. Stability of Perception under Time and Data (FR0/028/68), School of Architecture, Duncan of Jordanstone College of Art, University of Dundee, Dundee, Scotland, April 1977. 44. Green, C. H., and Brown, R. A., The Perception OJ and Attitudes Towards, Risk, Final Report: Vol. 4. Initial Experiments on Determining Satisfaction with Safety Levels (FR0/028/68), School of Architecture, Duncan of Jordanstone College of Art, University of Dundee, Dundee, Scotland, April 1977.
THE PERCEPTION
OF TECHNOLOGICAL
RISKS
293
45. Green, C. H., and Brown, R. A., Problems of Valuing Safety (Note N 70/78), Department of the Environment, Building Research Establishment, Borehamwood, Hertfordshire, England, 1978. 46. Greenberg, P. F., The Thrill Seekers, Human Behavior 6: 17-21 (April 1977). 41. Hammond, K. R., and Adleman, L., Science, Values and Human Judgment, Science 194: 389-396 (Oct. 22, 1976). 48. Harris, Louis and Associates, Inc., Harris Perspective 1979: A Survey of the Public and Environmental Activists on the Environment (59), Louis Harris and Associates, New York, 1979. 49. Harris, Louis and Associates, Inc., Risk in a Complex SocieQ, March & McClennon Public Opinion Survey, Chicago, 1980. 50. Harris, Louis and Associates, Inc., A Second Survey of Public and Leadership Attitudes Toward Nuclear Power Development in the United States, EBASCO, New York, 1976. 51. Hweitt, K., and Burton, I., The Hazardousness of a Place, University of Toronto Press, Toronto. 1971. 52. Hutton, J., and Miieti, D., Social Aspects of Earthquake, Paper presented at the Second International Conference on Microzonation, San Francisco, 1978. 53. Kahan, J. P., How Psychologists Talk About Risk (P-6403), The Rand Corporation, Santa Monica, Calif., Oct. 1979. 54. Kahneman, D., and Tversky, A., On the Psychology of Prediction, Psychological Review 80: 237-25 1 (July 1973). 55. Kahneman, D., and Tversky, A., Prospect Theory: An Analysis of Decision Under Risk, Econometrica 47: 263-291 (March 1979). 56. Kasper, R. G., Perceived Risk: Implications for Policy, Impacts and Risks of Energy Strategies: Their Analysis and Role in Management, Academic, London, 1979. 57. Kasper, R., Perceptions of Risk and Their Effects on Decision Making, in Societal Risk Assessment: How Safe Is Safe Enough:‘, R. Schwing and W. Albers, eds., Plenum, New York, 1980, pp. 71-80. 58. Kasperson, R. E., Berk, G., Pijaka, D., Sharaf, A., and Wood, J., Public Opposition to Nuclear Energy: Retrospect and Prospect, Science, Technology and Human Values 5: 1 l-23 (Spring 1980). 59. Kates, R., Human Adjustment to Earthquake Hazard, in The Great Alaska Earthquake of 1964, Committee on the Alaska Earthquake, ed., National Academy of Sciences, Washington, D.C., 1970, pp. 7-31. 60. Keeney, R. L., and Kirkwood, C. W., Group Decision Making Using Cardinal Social Welfare Functions, Management Science 22: 430-437 (1975). 61. Keeney, R. L., and Raiffa, H., Decisions with Multiple Objectives: Preferences and Value Tradeofls, Wiley, New York, 1976. 62. Klausner, S., ed., Why Man Takes Chances: Studies in Stress-Seeking, Doubleday, Garden City, N.Y., 1968. 63. Kunreuther, H., Limited Knowledge and Insurance Protection, Public Policy 24: 227-261 (1976). 64. Kunreuther, H., Ginsberg, R., Miller, L., Sagi, P., Slavic, P., Borkan, B., and Katz, N., Disaster Insurance Protection: Public Policy Lessons, Wiley, New York, 1978. 65. La Porte, T., Public Attitudes Toward Present and Future Technology, Social Studies of Science 5: 373-391 (1975). 66. La Porte, T. R., and Metlay, D.. Technology Observed: Attitudes of a Wary Public, Science 188: 121-127 (April 11, 1975). 67. La Porte, T. R., and Metlay, D., They Watch and Wonder: Public Attitudes Toward Advanced Technology, University of California, Institute of Governmental Studies, Berkeley, 1975. 68. Lerch, I., Risk and Fear, New Scientist 185: 8-l 1 (Jan. 3, 1980). 69. Lichtenstein, S., Fischhoff, B., and Phillips, L. D., Calibration of Probabilities: The State of the Art, in Decision Making and Change in Human Affairs, H. Jungermann and G. de Zeeuw, eds., Reidel, Dordrecht, 1977. 70. Lichtenstein, S., Slavic, P., Fischhoff, B.. Layman, M., and Combs, B., Judged Frequency of Lethal Events, Journal of Experimental Psychology: Human Learning and Memov 4: 551-578 (1978). 71. Linstone, H., et al., The Multipll Perspective Concept: With Applications to Technology Assessment and Other Decision Areas, Futures Research Institute, Portland State University, Portland, Oregon, 1981, See also Technological Forecasting and Social Change 20 (4): 275-325 (198 1). 72. Lowrance, W., OfAcceptable Risk, Science and the Determination of Safety, Kaufman, Los Altos, Calif., 1976. 73. Maderthaner, R., Guttman, G., Swaton, E., and Otway, H. J., Effect of Distance on Risk Perception, Journal of Applied Psychology 63 (3): 380-382 (1978).
294
V.T. COVELLO
74. Maderthaner, R., Pahner, P., Guttman, G., and Otway, H. J., Perceptions of Technological Risk: The Effect of Confrontation (IIASA RM-76-53), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1976. 75. Marquis, D. G., and Reitz, H. J., Effects of Uncertainty on Risk Taking in Individual and Group Decisions, Behavioral Science 14: 281-288 (July 1969). 76. Maynard, W. S., Nealey, S. M., Hebart, J. A., and Lindell, M. L., PublicValues Associated wirh Nuclear Waste Disposal (BNWL-1997), Battelle Human Affairs Research Center, Seattle, 1976. 77. Mazur, A., Disputes Between Experts, Minerva 11: 55-81 (1973). 78. Mazur. A., Opposition to Technological Innovation, Minerva 13: 58-81 (1975). 79. McEnvoy, J., The American Concern with the Environment, in Natural Resources and the Environment, W. R. Burch, Jr. et al., eds., Harper & Row, New York, 1972. 80. Melber. B. D., Nealey, S. M., Hammersla, .I., and Rankin, W. L., Nuclear Power and the Public: Analysis of Collected Survey Research (PNG2430), Battelle Human Affairs Research Center, Seattle, 1977. 8 1. Mileti, D., Human Adjustment to the Risk of Environmental Extremes, Sociology and Social Research 64 (3): 327-347 (April 1980). 82. Mileti, D., Natural Hazard Warning Systems in the United Stales, Monograph 13, University of Colorado, Institute of Behavioral Science, Boulder, 1975. 83. Mileti, D., Hutton, J., and Sorensen, J., Earthquake Prediction Response and Options for Public Policy, University of Colorado, Institute of Behavioral Science, Boulder, 1981. 84. Mitchell, R. C., Public Opinion on Environmental Issues: Results of a National Public Opinion Survey, Council on Environmental Quality, Department of Agriculture, Department of Energy, and Environmental Protection Agency, Washington, D.C., 1980. 85. Mitchell, R. C.. Silent Spring/Solid Majorities, Public Opinion 2 (Aug.-Sept. 1979). 86. National Academy of Sciences, A Program of Studies on the Socioeconomic Effects of Earthquake Predictions, National Academy of Sciences, National Research Council. Washington, D.C., 1978. 87. National Council on Radiation Protection and Measurements, Percepfions of Risk; Proceedings of the Fifteenth Annual Meeting, March 14-15, 1979, National Council of Radiation Protection and Measurements, Washington, D.C., March 1980. 88. Nelkin. D., Nuclear Power and Its Critics, Cornell University Press, Ithaca, N.Y., 1971. 89. Nelkin, D., The Political Impact of Technical Expertise, Social Studies ofScience 5: 35-54 (1975). 90. Nelkin, D., Some Social and Political Dimensions of Nuclear Power: Examples from Three Mile Island, American Political Science Review 75: 132-145 (March 1981). 91. Nelkin, D., Technological Decisions and Democracy, Sage Publications, Beverly Hills, Calif., 1977. 92. Nelkin, D., and Pollack, M., Political Parties and the Nuclear Energy Debate in France and Germany, Comparative Politics (Jan. 1980). 93. O’Hare, M., Not on My Block You Don’t: Facility Siting and the Strategic Importance of Compensation, Public Policy 25 (Fall 1977). 94. Okrent, D., and Whipple, C., An Approach to Societal Risk Acceptance Criteria and Risk Management (UCLA-ENG-7746). University of California, School of Engineering and Applied Science, Los Angeles, June 1977. 95. Opinion Research Corporation, Public Attitudes Toward Environmental Trade-Offs, ORC Public Opinion Index 33: l-8 (Aug. 1975). 96. Otway, H. J., The Perception of Technological Risks: A Psychological Perspective, in Technological Risk: Its Perception and Handling in the European Community, M. Dierkes, S. Edwards. and R. Coppock, eds., Oelgeschlager, Gunn and Hain, Cambridge, Mass., 1980, pp. 34-45. 97. Otway. H. J., Risk Assessment and Societal Choices (IIASA RM-75-2), International Institute for Applied Systems Analysis, Laxenburg, Austria, Feb. 1975. 98. Otway, H. J.. et al., On the Social Aspects of Risk Assessment, Journal of the Society for Industrial and Applied Mathematics (1977). 99. Otway. H. J., and Cohen, J. J., Revealed Pwferences: Comments on the Starr Benefit-Risk Relationships (IIASA RM-75-5), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1975. 100. Otway, H. J., and Fishbein, M., Public Attitudes and Decision Making (IIASA RM-77-54). International Institute for Applied Systems Analysis, Laxenburg, Austria, 1977. 101. Otway, H. J., and Fishbein, M., The Determinants of Attitude Formation: An Application to Nuclear Power (IIASA RM-7&80), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1976.
THE PERCEPTION
OF TECHNOLOGICAL
RISKS
295
102. Otway, H. J., Maderthaner, R., and Gunman, G., Avoidance Response to the Risk Environment: A CrossCultural Comparison (IIASA RM-75-14), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1975. 103. Otway, H. J., Maurer, D., and Thomas, K., Nuclear Power, The Question of Public Acceptance, Futures 10: 109-l 18 (April 1978). 104. Otway, H. J., Pahner, P. D., and Linnerooth, J., Social V&es in Risk Acceptance (IIASA RM-7%54), International Institute for Applied Systems Analysis, Laxenburg, Austria, Nov. 1975. 105. Pahner, P. D., The Psychological Displacement of Anxiety: An Application to Nuclear Power, in RiskBenefit Methodology and Application (UCLA-ENG-7598). D. Okrent, ed., University of California, Los Angeles, Dec. 1975. 106. Pahner, P. D., A Psychological Perspective of the Nuclear Energy Controversy (IIASA RM-76-67), International Institute for Applied System Analysis, Laxenburg, Austria, 1976. 107. Payne, J. W., Relation of Perceived Risk to Preferences Among Gamblers, Journal of Experimental Psychology: Human Perception and Performance 104: 86-94 (1975). 108. Pearce, D. W., The Nuclear Power Debate Is About Values, Nature 274: 200 (1978). 109. Pearce, D. W., The Preconditions for Achieving Consensus in the Context of Technological Risk, in Technological Risk: Its Perception and Handling in the European Community, M. Dierkes, S. Edwards, and R. Coppock, eds., Oelgeschlager, Gunn and Hain, Cambridge, Mass., 1980. 110. Powers, W. T., Behavior: The Control of Perception, Aldine, Chicago, 1973. 111. Pratt, J. W., Raiffa, H., and Schlaifer, R., The Foundations of Decision Under Uncertainty, The American Statistical Association
Journal
59: 353-376
(1964).
112. Raiffa, H., Decision Analysis: Introductory Lectures on Choices Under Uncertainty, Addison-Wesley, Reading, Mass., 1968. 113. Rapoport, A., and Wallsten, T. S., Individual Decision Behavior, Annual Review of Psychology 23: 131-175
(1972).
114. Ravetz, J. R., Public Perceptions of Acceptable Risks as Evidence for Their Cognitive, Technical, and Social Structure, in Technological Risk: Its Perception and Handling in the European Community, M. Dierkes, S. Edwards, and R. Coppock, eds., Oelgeschlager, Gunn, and Hain, Cambridge, Mass. 1980, pp. 46-57. 115. Rethans, A., An Investigation of Consumer Perceptions of Product Hazards, Unpublished Ph.D. dissertation, University of Oregon, 1979. 116. Ross, L., The Intuitive Psychologist and His Shortcomings, in Advances in Social Psychology, L. Berkowitz, ed., Academic, New York, 1977. 117. Rowe, W. E., An Anatomy of Risk, Wiley, New York, 1977. 118. Sapolsky, H. M., Science, Voters, and the Fluoridation Controversy, Science 162: 427-433 (1958). 1 19. Sjoberg, L., Risk Generation and Risk Assessment in a Social Perspective, Foresight, the Journal of Risk Management
3: 4-12
(1978).
120.
Sjoberg, L., Strength of Belief and Risk, Policy Sciences 2: 39-52 (Aug. 1979). 121. Slavic, P., Assessment of Risk-Taking Behavior, Psychological Bulletin 61: 220-233 (1964). 122. Slavic, P., Choice Between Equally Valued Alternatives, Journal of Experimental Psychology: Human Perception and Performance 1: 28&287 (1975). 123. Slavic, P., and Fischhoff, B., Cognitive Process and Societal Risk Taking, in Cognition and Sociefal Behavior, J. S. Carroll and J. W. Payne, eds., Lawrence Erlbaum Associates, Potomac, Md., 1976. 124. Slavic, P., Fischhoff, B., and Lichtenstein, S., Accident Probabilities and Seat Belt Usage: A Psychological Perspective, Accident Analysis and Prevention 10: 281-285 (1978). 125. Slavic, P., Fischhoff, B., and Lichtenstein, S., Behavioral Decision Theory, Annual Review of Psychology 28: l-39
(1977).
P., Fischhoff, B., and Lichtenstein, S., Characterizing Perceived Risk, in Technological Hazard Management, R. W. Kates and C. Hohenemser, eds, Oelgeschlager, Gunn and Hain, Cambridge, Mass., 1981. 127. Slavic, P., Fischhoff, B., and Lichtenstein, S.. Facts and Fears: Understanding Perceived Risk, in Societal Risk Assessment: How Safe Is Safe Enough?, R. Schwing and W. Albers, Jr., eds., Plenum, New York, 1980, pp. 181-216. 128. Slavic, P., Fischhoff, B., and Lichtenstein, S., Informing People about Risk, in Product Labeling and Health Risks (Banbury Report 6), L. Morris, M. Maris, and I. Barofsky, eds., Cold Spring Harbor Laboratory, Cold Spring Harbor, N.Y., 1980. 129. Slavic, P., Fischhoff, B., and Lichtenstein, S., Rating the Risks, Environment 21 (3): 14-39 (April 1979). 126. Slavic,
296
V.T. COVELLO
130. Slavic, P., Fischhoff, B., and Lichtenstein, S., Risky Assumptions, Psychology Today 14: 44-45, 47-48 (June 1980). 13 1. Slavic, P., Fischhoff, B., Lichtenstein, S., Corrigan, B., and Combs, B., Preference for Insuring Against Probable Small Losses: Insurance Implications, Journal of Risk and Insurance 45: 237-258 (June 1977). 132. Slavic, P., Kunreuther, H., and White, Cl., Decision Processes, Rationality and Adjustments to Natural Hazards, in Natural Hazurds: Local, National, and Global, G. F. White, ed., Oxford University Press, New York, 1974. 133. Slavic, P., Lichtenstein, S., and Fischhoff, B., Images of Disaster: Perception and Acceptance of Risks from Nuclear Power, in Energy Risk Management, G. Goodman and W. Rowe, eds., Academic. London, 1979. 134. Spangler. M. B., Risks and Psychic Costs of Alternative Energy Sources for Generating Electricity, The Energy Journal (Jan. 1981). 135. Starr, C., Social Benefit versus Technological Risk, Science 165: 1232-1238 (Sept. 19, 1969). 136. Starr, C., Some Comments on the Public Perception of Personal Risk and Benefit, in Risk vs. Benefit: Solution or Dream? H. J. Otway, ed., Los Alamos National Laboratory, Los Alamos, N.M., 1971. 137. Starr, C., and Whipple, C., Risk of Risk Decisions, Science 208: 1114-l 119 (June 1980). 138. Stumpf, S. E., Culture, Values, and Food Safety, BioScience 28: 186-190 (March 1978). 139. Svenson, O., Are We All Among the Better Drivers?, Unpublished report, Department of Psychology, University of Stockholm, Stockholm, Sweden, 1979. 140. Swaton, E., Maderthaner, R., Pahner, P. D., Guttman, G., and Otway, H. J., The Determinants of Risk Perception: A Survey (IIASA RM-76Xx), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1976. 141. Tamerin, T., and Resnick, L. P., Risk Taking by Individual Option--Case Study: Cigarette Smoking, Perspectives on Benefit-Risk Decision Making, National Academy of Engineering, Washington, D.C., 1972. pp. 73-84. 142. Thomas, K., Maurer, D., Fishbein, M., Otway, H., Hinkle, R., and Simpson, D., A Comparative Study of Public Beliefs About Five Energy Systems (IIASA RR-Et&l), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1979. 143. Thomas, K., Swaton, E., Fishbein, M., and Otway, H., Nuclear Energy: The Accuracy of Policy Makers’ Perceptions of Public Beliefs (IIASA RR-E&2), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1979. 144. Thompson, M., Aesthetics of Risk: Context or Culture’?, in Societal Risk Assessment: How Safe Is Safe Enough?, R. Schwing and W. Albers, eds., Plenum, New York, 1980, pp. 273-286. 145. Thomgate. W., Efficient Decision Heuristics, Behavioral Science 25: 219-225 (1980). 146. Tubiana, M., One Approach to the Study of Public Acceptance, in Directions in Energy Policy, B. Kursunoglu and A. Perlmutter, eds., Ballinger, Cambridge, Mass., 1979. 147. Tversky, A., Elimination by Aspects: A Theory of Choice, Psychological Review 79: 281-299 (1972). 148. Tversky, A., and Kahneman, D., The Framing of Decisions and the Psychology of Choice, Science 211: 1453-1458 (1981). 149. Tversky, A., and Kahneman, D., Availability: A Heuristic for Judging Frequency and Probability, Cognitive Psychology 4: 207-232 (1973). 150. Tversky, A., and Kahneman, D., Judgment Under Uncertainty: Heuristics and Biases, Science 185: 1124-l 131 (Sept. 27, 1974). 151. Tversky, A., and Sattath, S., Preferences Trees, Psychological Review 86: 542-573 (1979). 152. Velimirovic. H., An Anthropological View of Risk Phenomena (IIASA RM-75-Xx), International Institute for Applied Systems Analysis, Laxenburg, Austria, 1975. 153. Vlek, C., and Stallen, P. J., Judging Risks and Benefits in the Small and in the Large, Organizational Behavior and Human Performance 38 (Oct. 1981). 154. Vlek, C., and Stallen, P. J., Rational and Personal Aspects of Risk, Acta Psychologica 45 (1980). 155. Von Neuman, J., and Morgenstem, 0.. Theory of Games and Economic Behavior, Princeton University Press, Princeton, N.J., 1944. 156. Von Winterfeldt, D., Edwards, W., Anson, J., Stillwell, W., and Slavic, P., Development of a Methodology IO Evaluate Risks from Nuclear Electric Power Plants: Phase I-IdentifLinR Social Groups and Structuring Their Values and Concerns, Final Report to Sandia National Laboratories, Albuquerque, N.M., May 1980. 157. Von Winterfeldt, D., and Rios, M., Conflicts about Nuclear Power Safety: A Decision Theoretic Approach, in Proceedings of the ANSIENS Topical Meeting on Thermal Reactor Safety. M. H. Fontana and D. R. Patterson, eds., National Technical Information Service, Springfield, Va., 1980, pp. 696709.
THE PERCEPTION
OF TECHNOLOGICAL
RISKS
297
158. Weinstein, N. D., It Won’t Happen to Me: Cognitive and Motivational Sources of Unrealistic Optimism, Unpublished paper, Department of Psychology, Rutgers University, 1979. 159. Wendt, D., and Vlek, C., eds., Subjective Probability, Utility and Human Decision Making, Reidel, Dordrecht, 1974. 160. White, A., Global Summary of Human Responses to Natural Hazards: Tropical Cyclones, in Natural Hazards: Local, National, Global, G. White, ed., Oxford University Press, New York, 1974. 161. White, G., ed., Natural Hazards: Local, National, Global, Oxford University Press, New York, 1974. 162. White, G., Choice of Adjustments to Flood, Research paper no. 93, University of Chicago, Department of Geography, Chicago, 1964. 163. White, G., and Haas, J., Assessment of Research on Natural Hazards, MIT press, Cambridge, Mass., 1975. 164. White, G. F., Formation and Role of Public Attitudes, in Environmental Quality in a Growing Economy, H. Jarret, ed., Johns Hopkins University Press, Baltimore, 1966. 165. White, G. F., Human Responses to Natural Hazard, Perspectives on Benefit-Risk Decision Making, National Academy of Engineering, Committee on Public Engineering Policy, Washington, D.C., 1972. 166. Zebroski, E. L., Attainment of Balance in Risk-Benefit Perceptions, in Risk-Benefit Methodology and Application. Some Papers Presented at the Foundation Workshop, Asilomar, California (UCLA-ENG-7598), D. Okrent, ed., University of California, Los Angeles, 1975. Received 26 July 1982